Self-order systems for restaurants are already known. By way of example, in one self-order system, an order taking terminal is installed on each table in a restaurant, the terminals being connected to an order management computer via a network.
An order taking terminal comprises a display with a touch panel on which a menu of all items provided by the restaurant is displayed. A customer touches desired items in the menu. The terminal accepts the touched menu items and notifies the computer of the menu items.
For some types of menu item in the restaurant, menu items are treated as different when the items are of the same type but are different in serving size; for some drinks, different prices are set for the respective container size, that is, a small container, a medium-sized container, and a large container. If a restaurant dealing with such menu items adopts the above-described self-order system, the restaurant adds, for example, the items “small orange juice”, “medium orange juice”, and “large orange juice” to the list shown on the display so that customers can select any of the items.
However, simple addition of designations indicating the serving sizes may fail to let customers properly appreciate the differences between the volumes of the menu items. Thus, customers may order menu items with unexpected volumes. There has been a demand for an order taking system capable of taking orders from customers while letting customers intuitively appreciate the differences between the serving sizes of the menu items.